Generation of Halomethyl Radicals by Halogen Atom Abstraction and Their Addition Reactions with Alkenes

α-Aminoradicals undergo halogen
atom abstraction to form
halomethyl radicals in reactions initiated by the combination of tert-butyl hydroperoxide, aliphatic trialkylamine, halocarbon,
and copper­(I) iodide. The formation of the α-aminoradical circumvents
preferential hydrogen atom transfer in favor of halogen atom transfer,
thereby releasing the halomethyl radical for addition to alkenes.
The resulting radical addition products add the tert-butylperoxy group to form α-peroxy-β,β-dichloropropylbenzene
products that are convertible to their corresponding β,β-dichloro-alcohols
and to novel pyridine derivatives. Computational analysis clearly
explains the deviation from traditional HAT of chloroform and also
establishes formal oxidative addition/reductive elimination as the
lowest energy pathway.